Deontic Logic goes back to Ernst Mally’s 1926 work, Grundgesetze des Sollens: Elemente der Logik des Willens [Mally. E.: 1926, Grundgesetze des Sollens: Elemente der Logik des Willens, Leuschner & Lubensky, Graz], where he presented axioms for the notion ‘p ought to be the case’. Some difficulties were found in Mally’s axioms, and the field has much developed. Logic of Knowledge goes back to Hintikka’s work Knowledge and Belief [Hintikka, J.: 1962, Knowledge and Belief: An Introduction to the Logic of (...) the Two Notions, Cornell University Press] in which he proposed formal logics of knowledge and belief. This field has also developed quite a great deal and is now the subject of the TARK conferences. However, there has been relatively little work combining the two notions of knowledge (belief) with the notion of obligation. (See, however, [Lomuscio, A. and Sergot, M.: 2003, Studia Logica 75 63–92; Moore, R. C.: 1990, In J. F. Allen, J. Hendler and A. Tate (eds.), Readings in Planning, Morgan Kaufmann Publishers, San Mateo, CA]) In this paper we point out that an agent’s obligations are often dependent on what the agent knows, and indeed one cannot reasonably be expected to respond to a problem if one is not aware of its existence. For instance, a doctor cannot be expected to treat a patient unless she is aware of the fact that he is sick, and this creates a secondary obligation on the patient or someone else to inform the doctor of his situation. In other words, many obligations are situation dependent, and only apply in the presence of the relevant information. Thus a case for combining Deontic Logic with the Logic of Knowledge is clear. We introduce the notion of knowledge based obligation and offer an S5, history based Kripke semantics to express this notion, as this semantics enables us to represent how information is transmitted among agents and how knowledge changes over time as a result of communications. We consider both the case of an absolute obligation (although dependent on information) as well as the (defeasible) notion of an obligation which may be over-ridden by more relevant information. For instance a physician who is about to inject a patient with drug d may find out that the patient is allergic to d and that she should use d′ instead. Dealing with the second kind of case requires a resort to non-monotonic reasoning and the notion of justified belief which is stronger than plain belief, but weaker than absolute knowledge in that it can be over-ridden. This notion of justified belief also creates a derived notion of default obligation where an agent has, as far as the agent knows, an obligation to do some action a. A dramatic application of this notion is our analysis of the Kitty Genovese case where, in 1964, a young woman was stabbed to death while 38 neighbours watched from their windows but did nothing. The reason was not indifference, but none of the neighbours had even a default obligation to act, even though, as a group, they did have an obligation to take some action to protect Kitty. (shrink)

Many philosophers hold that luck excludes control-more precisely, that an event is lucky for you only if that event lies beyond your control. Call this the Lack of Control Requirement (LCR) on luck. Jennifer Lackey [2008] has recently argued that there is no such requirement on luck. Should such an argument succeed, it would (among other things) disable a main objection to the "libertarian" position in the free will debate. After clarifying the LCR, I defend it against both Lackey's argument (...) and a novel argument different in kind from Lackey's. I undermine each of these arguments by sketching a plausible error theory for its key intuition. For each argument, there's a natural reply available to its proponents. I show that these natural replies depend on certain mistaken general principles about luck. Neither Lackey's argument nor the novel argument I consider casts serious doubt on the LCR. [Word count: 147]. (shrink)

This paper has two main parts. In the first part, I argue that prominent moves in two related current debates in epistemology—viz., the debates over classical invariantism and the knowledge first movement—depend on one or the other of two claims about epistemic propriety: (1) Impropriety due to lack of a particular epistemic feature suffices for epistemic impropriety; and (2) Having justification to believe P suffices for having warrant to assert P. In the second part, I present and defend novel arguments (...) against both claims. (shrink)

It has long been debated whether objects are ‘sortally’ individuated. This paper begins by clarifying some of the key terms in play—in particular, ‘sortal’, ‘individuation’, and ‘object’. The term ‘individuation’ is taken to have both a cognitive and a metaphysical sense, in the former denoting the singling out of an object in thought and in the latter a determination relation between entities. ‘Sortalism’ is defined as the doctrine that only as falling under some specific sortal concept can an object be (...) successfully singled out in thought. It is argued that such a view is too strong, but that a weaker one, ‘categorialism’, can be defended, this implying that a thinker cannot successfully single out an object in thought without having at least an implicit grasp of the criterion of identity that the object satisfies. (shrink)

There is a widespread assumption that the classical work in philosophical semantics of Saul Kripke (1980) and Hilary Putnam (1975) has taught us that the essences of natural kinds of substances, such as water and gold, are discoverable only a posteriori by scientific investigation. It is such investigation, thus, that has supposedly revealed to us that it is an essential property of water that it is composed of H2O molecules. This is the way in which Scott Soames, in a recent (...) paper, makes the point in the case of water and H2O: [Here is] how a Kripkean explanation of the necessary a posteriority of [‘Water = H2O’] would go – or at any rate my version of it. The account holds that ‘water’ is a non-descriptive, directly-referential term designating a substance – where substances are taken to be physically constitutive kinds (instances of which share the same basic physical constitution). It is further assumed that a kind of this sort may have different instances in different world-states, and that if a and b are kinds with the same instances in all possible world-states, then a is b. These are clearly metaphysical assumptions, to which we add the natural corollary that for any substance, s, if, in some possible world-state, instances of s have a certain molecular structure, then instances of s have that structure in every world-state. In other words, we assume that it is an essential property of a substance that instances of it have the molecular structure they do. From this it follows that [‘Water = H2O’] is necessary if true, and that ‘H2O’– which I take to be equivalent to ‘the substance instances of which have a molecular structure with two hydrogen atoms and one oxygen atom’– is a rigid designator. Being true, [‘Water = H2O’] is, therefore, necessary. Since knowing the proposition it expresses requires knowing of a certain substance that its instances have a particular chemical structure, [‘Water = H2O’] is knowable only a posteriori. (Soames 2007: 36). (shrink)

For the good that I would, I do not; but the evil which I would not, that I do. Now if I do that I would not, it is no more I that do it, but sin that dwelleth in me. Romans 7.19-20.

Substantial change occurs when a persisting object of some kind either begins or ceases to exist. Typically, this happens when one or more persisting objects of another kind or kinds are subjected to appropriate varieties of qualitative or relational change, as when the particles composing a lump of bronze are rearranged so as to create a statue. However, such transformations also seem to result, very often, in cases of spatiotemporal coincidence, in which two numerically distinct objects of different kinds exist (...) in exactly the same place at the same time, such as a statue and a lump of bronze. Various attempts to resist this way of describing the results of such transformations are examined and found wanting and objections to the possibility of cases of spatiotemporal coincidence are rebutted. (shrink)

John Heil's new book (Heil 2003) is remarkable in many ways. In a concise, lucid and accessible manner, it develops a complete system of ontology with many strikingly original features and then applies that ontology to fundamental issues in the philosophy of mind, with illuminating results. Although Heil acknowledges his intellectual debts to C. B. Martin (p. viii), he is unduly modest about his own contribution to the development and application of this novel metaphysical system. A full examination of the (...) position that Heil defends would require a book in itself, so I shall limit myself to discussing some of its central themes and to explaining a few doubts that I have concerning some aspects of it. (shrink)

In this paper, I consider some issues involving a certain closure principle for Structural Justification, a relation between a cognitive subject and a proposition that’s expressed by locutions like ‘S has a source of justification for p’ and ‘p is justifiable for S’. I begin by summarizing recent work by Peter Klein that advances the thesis that the indicated closure principle is plausible but lacks Skeptical utility. I then assess objections to Klein’s thesis based on work by Robert Audi and (...) Anthony Brueckner. One finding is that the typical statement of the relevant closure principle can express a number of different closure principles, and that recognizing this helps to resolve certain disputes. (shrink)

Brian Cutter (Analysis 77: 278-287, 2017) argues that one of the most prominent versions of the consequence argument—viz., Peter van Inwagen’s (An Essay on Free Will. Oxford University Press, 1983) ‘Third Formal Argument’—does not support an incompatibility thesis that every paradigmatic compatibilist would reject. Justin Capes (Thought 8: 50-56, 2019) concedes Cutter’s conclusion concerning van Inwagen’s Third Formal Argument and tries to meet the important challenge that Cutter issues at the end of his paper—viz., articulate a promising version of the (...) consequence argument whose conclusion is an incompatibility thesis that every paradigmatic compatibilist would reject. After arguing that Capes’s response to Cutter’s challenge fails, I meet Cutter’s challenge by presenting and discussing a version of the consequence argument that focuses on ordinary human agents in circumstances that are ordinary for human agents. (shrink)

Soon after receiving Bouvet's interpretation of the hexagrams of the I ching as binary numbers, Leibniz communicated this application of his binary arithmetic to Hans Sloane in a letter published here for the first time. The letter also included a report on the observations of the variable star in the neck of the Swan by Gottfried Kirch. Sloane sent a copy of the scientific parts of the letter to Flamsteed.